Transparent, Flexible Strain Sensor Based on a Solution-Processed Carbon Nanotube Network

Abstract

The demands for transparent, flexible electronic devices are continuously increasing due to their potential applications to the human body. In particular, skin-like, transparent, flexible strain sensors have been developed to realize multifunctional human-machine interfaces. Here, we report a sandwich-like structured strain sensor with excellent optical transparency based on highly purified, solution-processed, 99% metallic CNT-polydimethylsiloxane (PDMS) composite thin films. Our CNT-PDMS composite strain sensors are mechanically compliant, physically robust, and easily fabricated. The fabricated strain sensors exhibit a high optical transparency of over 92% in the visible range with acceptable sensing performances in terms of sensitivity, hysteresis, linearity, and drift. We also found that the sensitivity and linearity of the strain sensors can be controlled by the number of CNT sprays; hence, our sensor can be applied and controlled based on the need of individual applications. Finally, we investigated the detections of human activities and emotions by mounting our transparent strain sensor on various spots of human skins.

Smart cord-rubber composites with integrated sensing capabilities by localised carbon nanotubes using a simple swelling and infusion method

“…A nearly linear relationship between sensing signal and applied load can be seen with sensing signals ( ) passing the zero value point, indicating a clear correlation between applied extension and sensing signal [10]. Similar findings were also observed in the other two systems (Figure 5b and 5c) with less obvious setting effects and slightly larger sensitivity owning to fewer conductive pathways arisen from a lower density of CNTs [32].…”

Ultrasensitive Strain Sensor Based on Separation of Overlapped Carbon Nanotubes

“…Generally, the performance of stretchable strain sensors is evaluated by the sensitivity, sensing range, and stability . In the past decades, several efforts have been made to improve the sensing performances of strain sensors, and conductive nanomaterials such as metallic thin films, nanoparticles, nanowires, graphene, and carbon nanotubes (CNTs) coupled with stretchable elastomers have been widely proposed because of their excellent electrical and mechanical properties. With these efforts, there has been a remarkable improvement in strain sensors regarding sensing range and sensitivity (Table S1, Supporting Information).…”

Stretchable and calibratable graphene sensors for accurate strain measurement

“…[1][2][3][4][5][6] To reach high stretchability, fibres 7 and elastomers -Ecoflex rubber, 8,9 polydimethylsiloxane [10][11][12][13][14][15][16] and nature rubber 17 -have been composed with various electrically conductive fillers, including but not limited to metal nanowires, 1,18,19 Pt-coated polymer nanofibers, 20 carbon nanotubes, [21][22][23][24] graphene, 15,25,26 PEDOT:PSS, 27 carbon conductive grease 28 and carbonized silk. 29 The efforts have been focused on pursuing high linearity, 26,30 stretchability, 17,21 sensitivity 7,24,31,32 and cyclic stability, 26,[33][34][35] less hysteresis for resistivesensors 33,36 as well as other environmental properties. 31,37 Many sensors are designed as wearable devices to merely sense changes, [38][39][40] where the numerical readings of the s...…”